/* ============================================================
 *
 * This file is a part of digiKam project
 * https://www.digikam.org
 *
 * Date        : 2023-05-15
 * Description : geolocation engine based on Marble.
 *               (c) 2007-2022 Marble Team
 *               https://invent.kde.org/education/marble/-/raw/master/data/credits_authors.html
 *
 * SPDX-FileCopyrightText: 2023-2026 by Gilles Caulier <caulier dot gilles at gmail dot com>
 *
 * SPDX-License-Identifier: LGPL-2.1-or-later
 *
 * ============================================================ */

#include "MarbleAbstractPresenter.h"

// Qt includes

#include <QtMath>

// Local includes

#include "Quaternion.h"
#include "ViewportParams.h"
#include "MarbleLocale.h"
#include "MarbleMap.h"
#include "MarbleModel.h"
#include "Planet.h"
#include "GeoDataGeometry.h"
#include "GeoDataLatLonAltBox.h"
#include "GeoDataPlacemark.h"
#include "GeoDataLookAt.h"
#include "MarbleClock.h"
#include "digikam_debug.h"

namespace Marble
{
MarbleAbstractPresenter::MarbleAbstractPresenter(MarbleMap* map, QObject* parent)
    : QObject               (parent)
    , m_map                 (map)
    , m_physics             (this)
    , m_animationsEnabled   (false)
    , m_logzoom             (0)
    , m_zoomStep            (MarbleGlobal::getInstance()->profiles() & MarbleGlobal::SmallScreen ? 60 : 40)
    , m_viewAngle           (110)
{
}

MarbleAbstractPresenter::~MarbleAbstractPresenter()
{
}

qreal MarbleAbstractPresenter::zoom(qreal radius) const
{
    return (200.0 * log(radius));
}

qreal MarbleAbstractPresenter::radius(qreal zoom) const
{
    return pow(M_E, (zoom / 200.0));
}

void MarbleAbstractPresenter::rotateBy(const qreal deltaLon, const qreal deltaLat, FlyToMode mode)
{
    GeoDataLookAt target           = lookAt();
    GeoDataCoordinates coords(map()->viewport()->centerLongitude(), map()->viewport()->centerLatitude());
    GeoDataCoordinates movedCoords = coords.moveByBearing(-map()->heading() * DEG2RAD, -deltaLat * DEG2RAD);
    movedCoords                    = movedCoords.moveByBearing((-map()->heading() - 90) * DEG2RAD,
                                                               -deltaLon * DEG2RAD * map()->viewport()->polarity());

    target.setLongitude(movedCoords.longitude());
    target.setLatitude(movedCoords.latitude());

    flyTo(target, mode);
}

void MarbleAbstractPresenter::flyTo(const GeoDataLookAt& newLookAt, FlyToMode mode)
{
    if (!m_animationsEnabled || (mode == Instant))
    {
        const int radius    = qRound(radiusFromDistance(newLookAt.range() * METER2KM));
        qreal const zoomVal = zoom(radius);

        // Prevent exceeding zoom range. Note: Bounding to range is not useful here

        if ((qRound(zoomVal) >= minimumZoom()) && (qRound(zoomVal) <= maximumZoom()))
        {
            map()->setRadius(radius);
            m_logzoom                    = qRound(zoom(radius));
            GeoDataCoordinates::Unit deg = GeoDataCoordinates::Degree;
            map()->centerOn(newLookAt.longitude(deg), newLookAt.latitude(deg));

            Q_EMIT zoomChanged(m_logzoom);
            Q_EMIT distanceChanged(distanceString());
        }
    }
    else
    {
        m_physics.flyTo(newLookAt, mode);
    }
}

QString MarbleAbstractPresenter::distanceString() const
{
    // distance() returns data in km, so translating to meters

    qreal dist           = distance() * KM2METER, convertedDistance;

    MarbleLocale::MeasureUnit unit;
    MarbleLocale* locale = MarbleGlobal::getInstance()->locale();
    locale->meterToTargetUnit(dist, locale->measurementSystem(), convertedDistance, unit);
    QString unitString   = locale->unitAbbreviation(unit);

    return QString::fromUtf8("%L1 %2").arg(convertedDistance, 8, 'f', 1, QLatin1Char(' '))
           .arg(unitString);
}

GeoDataLookAt MarbleAbstractPresenter::lookAt() const
{
    GeoDataLookAt result;

    result.setLongitude(map()->viewport()->centerLongitude());
    result.setLatitude(map()->viewport()->centerLatitude());
    result.setAltitude(0.0);
    result.setRange(distance() * KM2METER);

    return result;
}

qreal MarbleAbstractPresenter::distance() const
{
    return distanceFromRadius(radius());
}

qreal MarbleAbstractPresenter::distanceFromRadius(qreal radius) const
{
    // Due to Marble's orthographic projection ("we have no focus")
    // it's actually not possible to calculate a "real" distance.
    // Additionally the viewing angle of the earth doesn't adjust to
    // the window's size.
    //
    // So the only possible workaround is to come up with a distance
    // definition which gives a reasonable approximation of
    // reality. Therefore we assume that the average window width
    // (about 800 pixels) equals the viewing angle of a human being.

    return (model()->planet()->radius() * 0.4
            / radius / tan(0.5 * m_viewAngle * DEG2RAD));
}

qreal MarbleAbstractPresenter::radiusFromDistance(qreal distance) const
{
    return (model()->planet()->radius() /
           (distance * tan(0.5 * m_viewAngle * DEG2RAD) / 0.4));
}

int MarbleAbstractPresenter::polarity() const
{
    return map()->viewport()->polarity();
}

int MarbleAbstractPresenter::zoom() const
{
    return m_logzoom;
}

int MarbleAbstractPresenter::minimumZoom() const
{
    return map()->minimumZoom();
}

int MarbleAbstractPresenter::maximumZoom() const
{
    return map()->maximumZoom();
}

void MarbleAbstractPresenter::setZoom(int newZoom, FlyToMode mode)
{
    // It won't fly anyway. So we should do everything to keep the zoom value.

    if (!m_animationsEnabled || (mode == Instant))
    {
        // Check for under and overflow.

        if      (newZoom < minimumZoom())
        {
            newZoom = minimumZoom();
        }
        else if (newZoom > maximumZoom())
        {
            newZoom = maximumZoom();
        }

        // Prevent infinite loops.

        if (newZoom == m_logzoom)
        {
            return;
        }

        map()->setRadius(radius(newZoom));
        m_logzoom = newZoom;

        Q_EMIT zoomChanged(m_logzoom);
        Q_EMIT distanceChanged(distanceString());
    }
    else
    {
        GeoDataLookAt target = lookAt();
        target.setRange(KM2METER * distanceFromZoom(newZoom));
        flyTo(target, mode);
    }
}

void MarbleAbstractPresenter::zoomView(int zoom, FlyToMode mode)
{
    setZoom(zoom, mode);
}

void MarbleAbstractPresenter::zoomViewBy(int zoomStep, FlyToMode mode)
{
    setZoom(zoom() + zoomStep, mode);
}

void MarbleAbstractPresenter::zoomIn(FlyToMode mode)
{
    if (map()->tileZoomLevel() < 0)
    {
        zoomViewBy(m_zoomStep, mode);
    }
    else
    {
        qreal radiusVal      = map()->preferredRadiusCeil(map()->radius() / 0.95);
        radiusVal            = qBound(radius(minimumZoom()), radiusVal, radius(maximumZoom()));

        GeoDataLookAt target = lookAt();
        target.setRange(KM2METER * distanceFromRadius(radiusVal));

        flyTo(target, mode);
    }
}

void MarbleAbstractPresenter::zoomOut(FlyToMode mode)
{
    if (map()->tileZoomLevel() <= 0)
    {
        zoomViewBy(-m_zoomStep, mode);
    }
    else
    {
        qreal radiusVal      = map()->preferredRadiusFloor(map()->radius() * 0.95);
        radiusVal            = qBound(radius(minimumZoom()), radiusVal, radius(maximumZoom()));
        GeoDataLookAt target = lookAt();

        target.setRange(KM2METER * distanceFromRadius(radiusVal));

        flyTo(target, mode);
    }
}

void MarbleAbstractPresenter::zoomAtBy(const QPoint& pos, int zoomStep)
{
    qreal radiusVal;

    if (map()->tileZoomLevel() <= 0)
    {
        radiusVal = radius(zoom() + zoomStep);
    }
    else
    {

        radiusVal = zoomStep > 0 ? map()->preferredRadiusCeil(map()->radius() / 0.95) :
                    map()->preferredRadiusFloor(map()->radius() * 0.95);
        radiusVal = qBound(radius(minimumZoom()), radiusVal, radius(maximumZoom()));
    }

    zoomAt(pos, distanceFromRadius(radiusVal));
}

qreal MarbleAbstractPresenter::distanceFromZoom(qreal zoom) const
{
    return distanceFromRadius(radius(zoom));
}

qreal MarbleAbstractPresenter::zoomFromDistance(qreal distance) const
{
    return zoom(radiusFromDistance(distance));
}

void MarbleAbstractPresenter::goHome(FlyToMode mode)
{
    qreal homeLon = 0;
    qreal homeLat = 0;
    int homeZoom  = 0;

    model()->home(homeLon, homeLat, homeZoom);

    GeoDataLookAt target;
    target.setLongitude(homeLon, GeoDataCoordinates::Degree);
    target.setLatitude(homeLat, GeoDataCoordinates::Degree);
    target.setRange(1000 * distanceFromZoom(homeZoom));

    flyTo(target, mode);
}

void MarbleAbstractPresenter::moveByStep(int stepsRight, int stepsDown, FlyToMode mode)
{
    int polarity = map()->viewport()->polarity();
    qreal left   = polarity * stepsRight * moveStep();
    qreal down   = stepsDown * moveStep();

    rotateBy(left, down, mode);
}

qreal MarbleAbstractPresenter::moveStep() const
{
    int width  = map()->width();
    int height = map()->height();

    if (radius() < qSqrt((qreal)(width * width + height * height)))
    {
        return (180.0 * 0.1);
    }
    else
    {
        return (180.0 * qAtan((qreal)width
                / (qreal)(2 * radius())) * 0.2);
    }
}

int MarbleAbstractPresenter::radius() const
{
    return map()->radius();
}

void MarbleAbstractPresenter::setRadius(int radiusVal)
{
    Q_ASSERT(radiusVal >= 0);

    bool adjustRadius   = radiusVal != map()->radius();
    qreal const zoomVal = zoom(radiusVal);

    // Prevent exceeding zoom range

    if      (zoomVal < minimumZoom())
    {
        radiusVal = radius(minimumZoom());
        adjustRadius = true;
    }
    else if (zoomVal > maximumZoom())
    {
        radiusVal = radius(maximumZoom());
        adjustRadius = true;
    }

    if (adjustRadius)
    {
        map()->setRadius(radiusVal);
        m_logzoom = qRound(zoomVal);

        Q_EMIT zoomChanged(m_logzoom);
        Q_EMIT distanceChanged(distanceString());
    }
}

// NOTE: Moved from MarbleWidgetInputHandlerPrivate - fits more here now

void MarbleAbstractPresenter::zoomAt(const QPoint& pos, qreal newDistance)
{
    Q_ASSERT(newDistance > 0.0);

    qreal destLat;
    qreal destLon;

    if (!map()->geoCoordinates(pos.x(), pos.y(), destLon, destLat, GeoDataCoordinates::Degree))
    {
        return;
    }

    const ViewportParams* now = map()->viewport();
    qreal x(0), y(0);

    if (!now->screenCoordinates(destLon * DEG2RAD, destLat * DEG2RAD, x, y))
    {
        return;
    }

    ViewportParams soon;
    soon.setProjection(now->projection());
    soon.centerOn(now->centerLongitude(), now->centerLatitude());
    soon.setSize(now->size());

    qreal newRadius = radiusFromDistance(newDistance);
    soon.setRadius(newRadius);

    qreal mouseLon, mouseLat;

    if (!soon.geoCoordinates(int(x), int(y), mouseLon, mouseLat, GeoDataCoordinates::Degree))
    {
        return;
    }

    const qreal lon = destLon - (mouseLon - map()->centerLongitude());
    const qreal lat = destLat - (mouseLat - map()->centerLatitude());

    GeoDataLookAt lookAt;
    lookAt.setLongitude(lon, GeoDataCoordinates::Degree);
    lookAt.setLatitude(lat, GeoDataCoordinates::Degree);
    lookAt.setAltitude(0.0);
    lookAt.setRange(newDistance * KM2METER);

    map()->viewport()->setFocusPoint(GeoDataCoordinates(destLon, destLat, 0, GeoDataCoordinates::Degree));
    flyTo(lookAt, Linear);
}

void MarbleAbstractPresenter::moveTo(const QPoint& pos, qreal factor)
{
    Q_ASSERT(factor > 0.0);

    qreal destLat;
    qreal destLon;
    map()->geoCoordinates(pos.x(), pos.y(), destLon, destLat, GeoDataCoordinates::Radian);

    GeoDataLookAt lookAt;
    lookAt.setLongitude(destLon);
    lookAt.setLatitude(destLat);
    lookAt.setAltitude(0.0);
    lookAt.setRange(distance() * factor * KM2METER);

    flyTo(lookAt);
}

void MarbleAbstractPresenter::centerOn(const qreal lon, const qreal lat, bool animated)
{
    GeoDataCoordinates target(lon, lat, 0.0, GeoDataCoordinates::Degree);
    centerOn(target, animated);
}

void MarbleAbstractPresenter::centerOn(const GeoDataCoordinates& position, bool animated)
{
    GeoDataLookAt target = lookAt();
    target.setCoordinates(position);
    flyTo(target, animated ? Automatic : Instant);
}

void MarbleAbstractPresenter::centerOn(const GeoDataLatLonBox& box, bool animated)
{
    if (box.isEmpty())
    {
        return;
    }

    int newRadius                    = radius();
    const ViewportParams* viewparams = map()->viewport();

    // prevent divide by zero

    if (box.height() && box.width())
    {
        // work out the needed zoom level

        int const horizontalRadius = (0.25 * M_PI) * (viewparams->height() / box.height());
        int const verticalRadius   = (0.25 * M_PI) * (viewparams->width()  / box.width());
        newRadius                  = qMin<int>(horizontalRadius, verticalRadius);
        newRadius                  = qMax<int>(radius(minimumZoom()), qMin<int>(newRadius, radius(maximumZoom())));
    }

    // move the map

    GeoDataLookAt target;
    target.setCoordinates(box.center());
    target.setAltitude(box.center().altitude());
    target.setRange(KM2METER * distanceFromRadius(newRadius));
    flyTo(target, animated ? Automatic : Instant);
}

void MarbleAbstractPresenter::centerOn(const GeoDataPlacemark& placemark, bool animated)
{
    const GeoDataLookAt* lookAt(placemark.lookAt());

    if (lookAt)
    {
        flyTo(*lookAt, animated ? Automatic : Instant);
    }

    else
    {
        bool icon                 = false;
        GeoDataCoordinates coords = placemark.coordinate(model()->clock()->dateTime(), &icon);

        if (icon)
        {
            centerOn(coords, animated);
        }
        else
        {
            centerOn(placemark.geometry()->latLonAltBox(), animated);
        }
    }
}

void MarbleAbstractPresenter::headingOn(qreal heading)
{
    map()->setHeading(heading);
}

void MarbleAbstractPresenter::setCenterLatitude(qreal lat, FlyToMode mode)
{
    centerOn(centerLongitude(), lat, mode);
}

void MarbleAbstractPresenter::setCenterLongitude(qreal lon, FlyToMode mode)
{
    centerOn(lon, centerLatitude(), mode);
}

qreal MarbleAbstractPresenter::centerLatitude() const
{
    return map()->centerLatitude();
}

qreal MarbleAbstractPresenter::centerLongitude() const
{
    return map()->centerLongitude();
}

ViewContext MarbleAbstractPresenter::viewContext() const
{
    return map()->viewContext();
}

void MarbleAbstractPresenter::setViewContext(ViewContext viewContext)
{
    map()->setViewContext(viewContext);
}

bool MarbleAbstractPresenter::animationsEnabled() const
{
    return m_animationsEnabled;
}

void MarbleAbstractPresenter::setAnimationsEnabled(bool enabled)
{
    m_animationsEnabled = enabled;
}

int MarbleAbstractPresenter::logzoom() const
{
    return m_logzoom;
}

void MarbleAbstractPresenter::setLogzoom(int value)
{
    m_logzoom = value;
}

int MarbleAbstractPresenter::zoomStep() const
{
    return m_zoomStep;
}

qreal MarbleAbstractPresenter::viewAngle() const
{
    return m_viewAngle;
}

MarbleMap* MarbleAbstractPresenter::map()
{
    return m_map;
}

const MarbleMap* MarbleAbstractPresenter::map() const
{
    return m_map;
}

MarbleModel* MarbleAbstractPresenter::model()
{
    return m_map->model();
}

const MarbleModel* MarbleAbstractPresenter::model() const
{
    return m_map->model();
}

ViewportParams* MarbleAbstractPresenter::viewport()
{
    return map()->viewport();
}

const ViewportParams* MarbleAbstractPresenter::viewport() const
{
    return map()->viewport();
}

void MarbleAbstractPresenter::setDistance(qreal newDistance)
{
    qreal minDistance = 0.001;

    if (newDistance <= minDistance)
    {
        qCDebug(DIGIKAM_GEOENGINE_LOG) << "Invalid distance: 0 m";

        newDistance = minDistance;
    }

    int newRadius = radiusFromDistance(newDistance);
    setRadius(newRadius);
}

void MarbleAbstractPresenter::setSelection(const QRect& region)
{
    QPoint tl = region.topLeft();
    QPoint br = region.bottomRight();

    qCDebug(DIGIKAM_GEOENGINE_LOG) << "Selection region: (" << tl.x() << ", " <<  tl.y() << ") ("
                                   << br.x() << ", " << br.y() << ")" << Qt::endl;

    const GeoDataLatLonAltBox box = viewport()->latLonAltBox(region);

    Q_EMIT regionSelected(box);
}

} // namespace Marble

#include "moc_MarbleAbstractPresenter.cpp"

